Production of buten-2-ol-4 compounds

ABSTRACT

Production of buten-2-ol-4 compounds by isomerization of buten1-ol-4 compounds in the presence of palladium or a compound thereof and hydrogen. The products are solvents or starting materials for the production of solvents, dyes, surface coatings and pest control agents.

United States Patent Overwien et al.

PRODUCTION OF BUTEN-2-OL-4 COMPOUNDS Inventors: Hermann Overwien, Ludwigshafen; Herbert Mueller, Frankenthal, both Foreign Application Priority Data Jan. 15, 1969 Germany ..P 19 01 709.5

U.S. Cl. ..260/468 R, 260/469, 260/476 R, 260/598, 260/599, 260/600, 260/602,

260/6ll R, 260/612 D, 260/612 R, 260/614 AA, 260/617 R, 260/642 Int. Cl. ....C07c 43/14, C07c 47/26, C07c 67/00 [451 Oct. 10,1972

[58] Field (Search ..260/49l, 642, 617 R, 61 l R, 260/614 AA, 598, 599, 468 R, 476 R, 469, 600, 602, 612 R, 6l2 D [56] References Cited UNITED STATES PATENTS 3,344,171 9/1967 Lemberg ..260/489 Primary ExaminerVivian Garner Attorney-Johnston, Root, OKeeffe, Keil, Thompson & Shurtleff [57] ABSTRACT Production of buten-2-0l-4 compounds by isomerization of buten-l-ol-4 compounds in the presence of palladium or a compound thereof and hydrogen. The products are solvents or starting materials for the production of solvents, dyes, surface coatings and pest control agents.

7 Claims, No Drawings PRODUCTION OF BUTEN-2-OL-4 COMPOUNDS The invention relates to a process for the production of buten-2-ol-4 compounds by isomerization of buten- 1-ol-4 compounds in the presence of palladium or a palladium compound and hydrogen.

It is known for Tetrahedron Letters, 20 2,9l I et seq. (1964) that in the presence of N-lithiumethylenediamine as a catalyst, allyl carbinol is partly isomerized into crotyl alcohol. It is also known that unsaturated alcohols can be isomerized in the presence of carbonyls of metals of group VIII of the Periodic System of Elements as catalysts. This method has the disadvantage however that numerous byproducts and secondary products, for example corresponding aldehydes, are obtained in the isomerization (Chem. Commun., 97 to 99 (1968), J. Amer. Chem. Soc., 85 1549 1963)).

The isomerization can be carried out purely thermally without using catalysts (Can..l.Chem., 46, 2225 l968)), but usually very high temperatures have to be used and this results in partial resinification of the starting compound.

An object of this invention is a new and more economical process for producing buten-2-ol-4 in a better yield and purity.

This and other objects are achieved and buten-2-ol-4 having the general formula:

where the individual radicals R, R, R, R and R may be identical or different and each denotes a hydrogen atom or an aliphatic radical, R may also denote a radical -CHO, R and R together with the carbon atoms situated between them may also be members of an alicyclic ring and/or R may also denote a cycloaliphatic, araliphatic or aromatic radical, or the radical where R denotes an aliphatic, cycloaliphatic, araliphatic or aromatic radical, can be obtained advantageously by isomerization of unsaturated alcohols by isomerizing a buten-l-ol-4 compound having the general formula:

where R, R, R, R and R have the meanings given above in the presence of hydrogen and of palladium and/or a compound of palladium.

The reaction may be represent in the case when 2- methylbuten-l-ol-4 is used by the following equation:

Contrasted with the said prior art methods, the process according to this invention give buten-2-ol-4 by a more economical method in better yields and higher purity.

Buten-l-ols-4 or their esters or ethers are used as starting materials having the general formula (ll). Preferred starting materials (I1) (and consequently preferred end products (1)) are those in whose formulas the individual radicals R, R, R, R and R are identical or different and each denoted a hydrogen atom or an alkyl radical having one to six carbon atoms, R may also denote the radical CI-l0, R and R together with the carbon atoms lying between them may also denote members of a five-membered, sixmembered or seven-membered alicyclic ring and/or R may also denote a cycloalltyl radical having five to seven carbon atoms, an aralkyl radical having seven to l2 carbon atoms, a phenyl radical, a naphthyl radical or the radical where R denotes an alkyl radical having one to six carbon atoms, a cycloalkyl radical having five to seven carbon atoms, an aralkyl radical having seven to 12 carbon atoms, a phenyl radical or a naphthyl radical. The said radicals may also bear groups and/or atoms which are inert under the reaction conditions, for example ether groups, as substituents.

For example the following buten-l-ol-4 compounds may be used as starting materials (ll): buten-l-ol-4; Z-methylbutenl -ol-4; l-formylbutenl 01-4; 2,3,4-trimethylbutenl -ol-4; 3-isobutylbuten-l -ol- 4; 4-hexylbutenl -ol-4; l-methylene-3-methylcyclohexanol-3; l -methylene-2-ethylcyclopentanol-3; l-methylenecyclohexanol-3; l-methylenecycloheptanol-3; and analogous ethyl, cyclohexyl, benzyl, phenyl or a-naphthyl ethers and acetic, cyclohexanecarboxylic, benzoic,a-naphthoic and dihydrocinnamic esters.

The reaction is can'ied out in the presence of palladium or a compound of palladium, generally in an amount of 0.01 to 5 percent by weight, preferably 0.l to 2 percent by weight, of palladium as finely divided metal and/or calculated as palladium in the form of its finely divided compounds, with reference to starting material (II). For example palladium black, palladium powder, or palladium bromide, arsenide, cyanide, chloride, nitrate, iodide, oxide, sulfide or sulfate or complex salts such as tetrachloropalladates, tetraminepalladium chloride, diamine palladium chloride or hexachloropalladates may be used as isomerization catalysts. The said catalysts may advantageously be applied in the conventional way to carriers, for example active carbon, barium sulfate, silica gel or zeolites, and the resultant supported catalysts used for the isomerization. Production of such supported catalysts may be carried out in any way, for example by impregnation of the carrier with the appropriate solution of a palladium salt, or by kneading or mixing while grinding the components. Reference is made to Houben-Weyl, Methoden der organischen Chemie," volume 4/2, pages 137 et seq, for details of the production of the catalysts, particularly supported catalysts.

The reaction is carried out in the presence of hydrogen, generally in an amount of l to 25 mole percent, preferably 5 to 50 mole percent, with reference to starting material (ll). Hydrogen may be supplied continuously or intermittently to the reaction and/or the catalyst itself may be freshly loaded with hydrogen after a certain reaction period. As a rule the starting material is isomerized at a temperature of from 0 to 250C, preferably from 30 to I50C, at atmospheric or superatmospheric pressure, for example up to 50 atmospheres, continuously or batchwise. Organic solvents which are inert under the reaction conditions such as ethers, for example diethyl ether, dioxane or tetrahydrofuran; alkanols, for example ethanol or isobutanol; aromatic or aliphatic hydrocarbons, for example heptane or benzene; or appropriate mixtures thereof may be used if desired. Solvents which under the reaction condition serve as hydrogen donors and are themselves dehydrogenated in the process, such as derivatives of cyclohexane, for example cyclohexenol or tetrahyd roacetophenone, may also be used.

lsomerization may be carried out as follows: the starting material (ll) and the catalyst, with or without a solvent, are kept for minutes to 6 hours at die reaction temperature in the presence of hydrogen. The end product is then separated from the mixture by a conventional method, for example by fractional distillation.

The compounds which can be prepared by the process according to the invention are solvents and valuable starting materials for the production of solvents, dyes, surface coatings and pesticides.

Reference is made to US. Patent No. 2,0l l,3 l 7 and Neftekhimiya, volume 4 (I964), pages 609 to 617 (part 4) as regards the use of the end products.

The Examples illustrate the invention.

Parts given in the following Examples denote parts by weight. They bear the same relation to parts by volume as the kilogram to the liter.

EXAMPLE 1 A mixture of 344 parts of 2-methylbuten-l-ol-4 and I part of palladized carbon 10 percent by weight of palladium) has 4,000 parts by volume of hydrogen passed into it with efficient stirring. The mixture is then heated for 6 hours at refluxing temperature (l25 to 130C) and the end product is separated by fractional distillation. 214 parts of 2-methylbuten-2-ol-4 is obtained having a boiling point of 14]"C at 760 mm. This is equivalent to 95 percent of the theory with respect to reacted starting material and 70 percent of the theory with respect to starting material used.

EXAMPLE 2 salt 4,000 parts by volume of hydrogen is passed with efficient stirring into a mixture of355 parts of buten-l-ol- 4 and 0.5 part of palladized carbon ([0 percent by weight of palladium). The mixture is then heated for 4 hours at l 10C The end product is separated by fractional distillation. A mixture of 160 parts of buten-l-ol- 4 and 181 parts of buten-2-ol-4 (crotyl alcohol) is obtained. The latter is separated from the starting material by distillation at 97C at 300 mm, the yield is 93 percent of the theory with reference to reacted starting material and 51 percent of the theory with reference to starting material used.

EXAMPLE 3 cent of the theory with reference to starting material used.

EXAMPLE 4 310 parts of l-methylene-3-methylcyclohexanol-3 is subjected to an isomerization reaction in the manner described in Example I. 260 parts of l,4-dimethylcyclohexen-l-ol-3 having a boiling point of 173C is obtained. This is a yield of percent of the theory with reference to starting material reacted and 84 percent of the theory with reference to starting material used.

EXAMPLE 5 parts of 2-methylene 4-acetoxybutanal-l is subjected to an isomerization reaction analogously to Example l. 45 parts of 2-methyl-4-acetoxy-2-lal having a boiling point of 52C at 30 mm is obtained. This is a yield of 30 percent of the theory with reference to starting material used.

We claim: I. A process for the production of buten-2-ol-4 compounds having the formula:

carbon atoms, a phenyl radical, a naphthyl radical or the radical where R denotes an alkyl radical of one to sm carbon atoms a cycloalltyl radical having five to seven carbon atoms, a hydrocarbon aralkyl radical of seven to [2 carbon atoms, a phenyl radical or a naphthyl radical by isomerization ofan unsaturated alcohol in the presence ofa catalyst at a temperature of0 to 250 C wherein a butenl -ol-4 compound having the form ula:

where R, R, R", R and R have the meanings given is isomerized in the presence of palladium metal or a palladium salt and hydrogen.

2. A process as in claim 1 wherein the isomerization is carried out in the presence of palladium in an amount of 0.0l to 5 percent by weight of palladium as a finely divided metal or calculated as palladium in the form of a finely divided palladium salt, with reference to starting material (ll).

3. A process as in claim 1 wherein the isomerization is carried out in the presence of palladium in an amount of 0.1 to 2 percent of palladium as finely divided metal or calculated as palladium in the form of a finely divided palladium salt with reference to starting material (II).

4. A process as in claim 1 wherein the isomerization is carried out in the presence of hydrogen in an amount of 1 to 25 mole percent with reference to starting material (ll).

5. A process as in claim 1 wherein the isomerization is carried out in the presence of hydrogen in an amount of 5 to 50 mole percent with reference to starting material (II).

6. A process as in claim 1 wherein the isomerization is carried out at a temperature of from 30 to C.

7. A process as in claim 1 wherein the isomerization is carried out in the presence of an organic solvent which is inert under the reaction conditions. 

2. A process as in claim 1 wherein the isomerization is carried out in the presence of palladium in an amount of 0.01 to 5 percent by weight of palladium as a finely divided metal or calculated as palladium in the form of a finely divided palladium salt, with reference to starting material (II).
 3. A process as in claim 1 wherein the isomerization is carried out in the presence of palladium in an amount of 0.1 to 2 percent of palladium as finely divided metal or calculated as palladium in the form of a finely divided palladium salt with reference to starting material (II).
 4. A process as in claim 1 wherein the isomerization is carried out in the presence of hydrogen in an amount of 1 to 25 mole percent with reference to starting material (II).
 5. A process as in claim 1 wherein the isomerization is carried out in the presence of hydrogen in an amount of 5 to 50 mole percent with reference to starting material (II).
 6. A process as in claim 1 wherein the isomerization is carried out at a temperature of from 30* to 150*C.
 7. A process as in claim 1 wherein the isomerization is carried out in the presence of an organic solvent which is inert under the reaction conditions. 